Mobile handsets have an inherently impoverished graphical user interface (GUI) with respect to desktop computers. Small screens and tiny keyboards are typical of mobile handsets that fit in your pocket. Recent so called smart phones have introduced the use of a touch screen in an attempt to simplify the user experience with his mobile handset. For instance, the touch interface of the iPhone® has revolutionized the mobile handset industry and brought whole new mobile user experiences. Touch-based interfaces have now become common-place through the adoption of smartphone and tablet touch screens.
In existing smart phones, application programs (AP) may be controlled through interactions such as touch inputs. Different touch inputs may control the AP in different ways. For instance, a user touching an AP icon will cause a control of the desktop GUI that will launch the AP corresponding to the touched icon.
A common interaction on a smart phone is to use a continuous, directional gesture or touch input to draw on the touch screen a continuous sequence to unlock the device. Such a known interaction is described in U.S. Pat. No. 8,136,053B1. A lock screen is a Graphical User Interface (GUI) displayed to the user when trying to reuse his electronic device after he activates its lock (screen) mode against unwanted use. An illustration of a known lock screen is displayed in FIGS. 4A-4B.
One implementation uses a series of nine circles form an unlock pattern and are displayed to the user in the lock screen GUI of FIG. 4A. These circles are presented to the user as guides to draw a line with his finger. While configuring the lock screen mode, the user is invited as in FIG. 4B to draw at the touch screen of the electronic device a continuous sequence joining a plurality of the nine circles. The continuous sequence—referred here after as the unlock sequence is characterized by a predefined shape 430 (here illustrated as a W shape). It is saved by the electronic device and will be requested with each user attempt to unlock his device. To facilitate the entry of the unlock sequence, the processor of the device may render a visual feedback (like the thick line 430) to the user by showing a line joining the circles as the user's finger 410 moves across the circles.
When detecting at the touch screen a touch input, the processor of the electronic device, when in the lock mode, will compare the shape of the detected touch input to the predefined shape after the user has discontinued his touch input. Provided the shapes are identical, the processor will unlock the device screen and the user will be able to resume interactions with the electronic device.
A problem with such a solution is that the unlock sequence may be visible to other people. Existing lock modes do not prevent undesired witnesses from seeing the unlock sequence nor being able to repeat it after stealing the electronic device.
Today there is still a need to an improved lock mode for an electronic device such as a smartphone. There is a further need for a lock mode that do not bring additional complexity to the unlocking of the device.